In principle making a some-of-the-web search engine is a tractable problem. Start by indexing known high quality, preferably moderated sites. Allow trusted user

In principle making a some-of-the-web search engine is a tractable problem. Start by indexing known high quality, preferably moderated sites. Allow trusted users to upload their bookmarks for indexing. And so on... My guess is the reason there are so few competitors is economics. You can't get investment as long as Google stock is a sure bet. Few will pay for your service as long as Google is answering their questions. Advertisers aren't interested as their money is more effectively spent on Google. Therefore you can't build an audience sure to lack of revenue/capital.